Improvement in arched bridges



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g JAMES B. EADS AND HENRY FLAD, 0F ST. LOUIS, MISSOURI.

Letters Patent No. 95,484, dated October 12, 1869.

IMPROVEMENT IN; ARCHED BRIDGES.

f"Il'fhe Schedule referred to n these Letters Patent and making part of the same To all whom t may concern Be it known that we, JAMES B. EADS and HENRY FLAI), of St. Louis, in the county of St. Louis, and State of Missouri, have made certain new and useful I mprovements-in Arched Bridges; and we do hereby declare that the following is a full and correct description thereof, reference being had to the accompanying drawings, and Vto the letters of reference marked thereon.

This invention relates to the manner of supporting the arches upon piens, in such wise that said piers shall be relieved of the iateral thrust usually arising thereon, thus permitting a light construction of such piers,in accordance with vertical pressure thereon, and with only such additional pressure or thrust as the friction caused by the devices here employed may exercise.

For said purposes, the adjoining ends of the arches at any pier will be connected with a proper jointpiece, and this will rest upon rollers, moving upon a rest-plate upon the pier.

To enable v,those herein skilled to make and use our said invention, we will now-l more fully describe the same, referring herein to the accompanying Figure 1 as an elevation; to Figure 2 as a sectional view near the pier.

We construct the arches A and A o'f the' usual materials, and in the usualI forms, abutting against the abutments B B', and vbeing connected therewith in proper manner.

0u the pier C we support said arches, in accordance with the nature of this invention, in the manner following:

joint-piece D, of suitable form to furnish a bearing.

Said piece D will be arranged with rollers cl.4 These move upon a suitable bearing or inondationplate, secured in the pier C. l

We form the arches A and A of such strength transmit the thrust from one to the otherarc-h, and pass the said thrust to the abutments; and, more especially, we make the said arches of such strength and stiffness that they will not be unduly distorted, and thus cause an excessive movement of the piece D upon the pier C.

Itis apparent that the pier C receives merely the vertical pressure caused by the load on said arches,

W'itnesses THG. SADLER, rlrros. SADLER Huster.

The ends a of the said arches abut against the 'and' stiffness that they may he able to resist and i and such friction-thrusts as the movement of the 

